Dovetailing machine



Feb. l, 1966 L G, BARANQZYK 3,232,327

DOVETAILING MACHINE Filed Feb. ll, 1963 TQ-Z 420 4 Sheets-Sheet l Fell l, 1966 J. G. BARANczYK 3,232,327

DOVETAILING MACHINE Filed Feb. ll 1963 4 Sheets-Sheet 2 ,l'f Il: :I: I." 2255]27 Fell 1, 1966 J. G. BARANczYK 3,232,327

DOVETAILING MACHINE Filed Feb. ll 1965 4 Sheets-Sheet 5 jme/flor Febl, 1966 J. G. BARANCZYK 3,232,327

DOVETAILING MACHINE Filed Feb. ll, 1963 4 Sheets-Sheet 4 United States Patent O 3,232,327 DOVETAILING MACHINE James G. Baranezyk, 208 Chicago St., Pulaski, Wis. Filed Feb. 11, 1963, Ser. No. 257,691 1 Claim. (Cl. 144;-85)

. This invention relates to a dovetailing machine, and, more particularly, to a machine adapted to cut the dovetail fittings, i.e., mortises and tenons, in two or more boards substantially simultaneously.

An important use of a dovetail fitting is in the c-onstruction of drawers, but heretofore this has been restricted to furniture of the higher quality grades because of the eX- pense involved. Many dovetailing machines have been known to the art for this purpose, but they have all been characterized by complexity in make-up and limited adaptability to different sized boards and drawers. This has meant special set-ups for each particular type drawer, necessitating restriction ofthe use of the prior art machine to high volume, relatively expensive furniture. It is not an uncommon phenomenon for a drawer of the slotted and glued type to come apart at the seams. Through the instant invention, this drawback is avoided, and, more importantly, dovetailing is now made available to the makers of relatively inexpensive furniture.

` The provision of a machine achieving this advantageous usage constitutes an important object of the invention-this being developed through the provision of a machine which is compact and simple in execution, yet rugged in construction, and which is adapted for a wide variety 4of drawer sizes, board thicknesses, etc.

Another object of the invention is to provide a novel guide in a dovetailing machine whereby lip and flush drawers are equally conveniently made via dovetailing. Still another object of the invention is to provide a machine having a unique adjustment feature which ladapts the machine for varying thickness boards, particujwhichz..

. g FIG. 1 is a perspective view, partially broken away, of `the inventive machine as seen from the operating end .,thereof;

FIG. 2 (on'thesecond drawing sheet) is a perspective YView of the machine of FIG. 1 but seen from the rear or work side thereof;

, FIG. 3 (on the third drawing sheet) is a vertical sectional ve'w, in fragmentary form, of the machine of FIGS. 1an-d 2 as viewed from the right and left sides,

respectively;

FIG. 4 is a Vtop plan sectional view, ytaken along the line 4-.4 as applied to FIG. 3;

FIG. 5 (on the fourth drawing sheet) is a fragmentary vertical sectional View taken along the line 5-5 as applied to' FIG. 3;

FIG. 6 is a fragmentary bottom view of the showing in FIG. 5; FIG. 7 is a fragmentary elevational view such as would be seen along the sight line 7 7 as applied to FIG. 5;

FIG. 8 (on the first drawing sheet) is a bottom plan view of the board carriage of the machine;

FIG. 9 is a fragmentary enlarged top view of the rack encircled as at A in FIG. 8;

ice

FIG. 11 (on the fourth drawing sheet) is a bottom plan view of the rack encircled as at B in FIG. 8;

FIG. l2 (on the second drawing sheet) is an enlarged fragmentary view of a router bit employed in conjunction with the invention machine;

FIG. 13 is a fragmentary elevational view, partially in section, of boards assembled within the dovetailing machine for forming a lip-type drawer;

FIG. 14 is a fragmentary elevational view, partially in section, of boards assembled for the purpose of making a flush-type drawer; and

FIG. 15 is a fragmentary perspective view of a liptype drawer corner.

In the illustration given, and with particular reference to FIG. 1, the numeral 20 designates generally a box-type frame for supporting the moving elements of the dovetailing machine. As seen in FIG. 2, the frame 20 supports a router carriage generally designated 21 and a board carriage 22. Still further, as seen in FIG. 5, the frame 2l) supports a motor carriage generally designated 23.

Operation in general The board carriage 22, during a dovetailing operation, moves interruptedly in one horizontal direction, i.e., the direction away from the handle 24. The handle 24 is employed for immobilizing the motor carriage 23. During the time the board carriage 22 is at rest, the router carriage 21 reciprocates with the router bits 25 rotating. This operation can be most readily appreciated from a consideration of FIG. 3, where the direction of reciprocating movement of the router carriage is designated by 26 and the interrupted movement of the board carriage 22 is into the paper. At the end of a given dovetailing cycle, the board carriage is returned in a direction out of the paper (insofar as FIG. 3 is concerned), which corresponds to movement of the carriage 22 to the left in FIG. 1, i.e., toward the handle 24.

The operation performed during these two carriage movements is illustrated in FIG. 13, wherein the direction of movement 26 is again indicated relative to the router carriage 21. The upper or board carriage 22 is seen to support a board 27, ultimately becoming the end board of a drawer generally designated 28 in FIG. 15. This board, at the conclusion of the dovetailing operation, is equipped with projections 29 and 30, developing a cavity as at 31 and constituting the mortise portion of the dovetail point. The side board 32 is also su-pported on the board carriage 22 and during reciprocation of the router bit 25 shaped to develop the tenon portion olf the dovetail joint which fits into the mortise 31. It will be appreciated that to engage the tenon portion 33 of the side board 32 with the mortise portion 31 of the end board 27, the side board 32 must be rotated 180 from its position in FIG. 13 and shifted one joint sideways in order to achieve the arrangement of FIG. 15.

.At Ythis juncture, it can be briefly pointed out that the only difference in the FIG. 13 and FIG. 14 showings lies relative to the provision of a lip 34 on the end Board carriage The board carriage 22 is seen in rather detailed form .in all of FIGS. 1-5, and constitutes the superstructure of FIG. 10 is a fragmentary side elevational view of the FIG. 9 rack;

the dovetailing machine. The board carriage 22 is made up of a bottom plate 35 (see FIG. 3 on the third drawing sheet), which is dovetail slotted as at 36 on its underside to receive dovetail tracks or rails 37 provided as part of the frame 20. Thus, the board frame 22 moves laterally horizontally along a guided path. Upstanding from the bottom plate 35 are side walls 38 and 39 (see FIGS. 1, 2 and 5), the showing in FIG. 3 being only of the side plate 39. Interconnecting the side plates 38 and 39 is a partition plate 40 which provides an opening as at 41 (designated only in FIG. 3), communicating the operating and work ends of the machine.

The side plates 38 and 39 are further tied together and rigiditied -by virtue of Stringer plates 42 and 43 (still referring to FIG. 3) which support a clamping mechanism generally designated 44 for securing the end board 27 against the plate 35, i.e., horizontally.

On the other side of the partition 40, the side plates 38 and 39 are connected by stringer plates 46 and 47 which provide a mounting for a second clamp generally designated 48 and which is employed to urge the side board 32 against the partition 40. Thus the side and end boards are orthogonally related, with the lower end of the side boards 32 resting against the board carriage 22, as is readily seen in FIGS. 13 and 14.

In the illustration given, the Stringer plates 46 and 47 support a pair of clamps 48, as can be appreciated from FIG. 2, while the stringers 42 and 43 support a pair of clamps 44, as seen in FIG. 1. Thus, with a board carriage 22 measuring slightly in excess of 12 between the insides of the side plates 38 and 39, it is possible to make all four sides of a 6" high drawer at one time, i.e., one interrupted horizontal movement of the board carriage 22. To this end, the machine is equipped with a pair of router bits 25, each mounted on the shafts of router motors 49 (see FIG. 2), the router motors 49 being secured to the router carriage 21 by means of brackets 50, as seen in FIG. 3 on the third drawing sheet.

Router carriage Before going into the description of the means for moving and positioning the board carriage 22, the router carriage 21 will be described. The router carriage 21 (see FIG. 2 on the second drarwing sheet) is equipped with a dovetail mortise portion along the sides as at 51. Received within the mortise 51 is a tenon 52 extending laterally from the frame 20. Thus, the router carriage 21 is adapted for horizontal movement perpendicular to the movement of the board carriage 22. As seen in FIG. 3 on the third drawing sheet, the router carriage 21 extends only a short distance beyond the partition 40 toward the 4operating end of the machine. This makes it possible to brin-g the main driving motor 53 up close to the underside of the board carriage 22, resulting in a compact machine, as can be appreciated from a consideration of FIG. l, where the frame 20 is supported on a table 54. The table 54 may be employed for supporting a dust-collection bag 55 (see FIG. 2), communicating by means of pipe 56 with a source of suction (not shown). The dust bag 55, by means of a conduit 56a, communicates with a suction hood 57 arranged over the router bits 25, as seen in dotted line in FIG. 3. In FIG. 2, the hood 57 has been removed from its position over the bits 2S and placed on the surface 54a so as to permit viewing of the bits.

As mentioned previously, the brackets 50 secure the router motors 49 to the underside of the router carriage 21, with suitable electrical connections at V58 (see FIG. 2) being provided for interconnection with a junction box generally designated 59 and which carries the main switch as at 59a (see FIG. l).

Router carriage reciprocating means The means for reciprocating the router carriage can be best seen in FIGS. and 6. As mentioned previously, the motor 53 is employed for this purpose, and is secured by means of a bracket 58 to the underside of the motor carriage 23, The motor carriage is mounted for horizontal movement into and out of the paper, as seen in FIG. 5, by means of guide rails 59 provided as part of the main frame 20. Only limited movement of the motor carriage 23 is required-to position the routers out of the way of the board carriage 22 during the return movement after a dovetailing operation is completed. This positioning of the motor carriage 23 is achieved through the handle 24, which is rigidly fixed to a cross shaft 60 (see also FIG. 7). A linkage as at 61 (see FIG. 3 on the third drawing sheet) is provided that interconnects the cross shaft 60 with the motor carriage 23. Thus, as the handle 24 is rotated, the motor carriage 23 is positioned accordingly. To define the limits of position of the motor carriage 23, the frame 20 is equipped with a bracket 62 (see FIG. 7 on the fourth drawing sheet), which slidably carries a threaded shaft as at 63 secured at one end as at 64 to a plate 65 fixed to the handle 24. Thus, move-ment of the handle 24 in the clocklwise direction seen in FIG. 7 is opposed by the spring 63, and the handle 24 is maintained in its extreme clock-wise position by means of a holder 66 also mounted on the frame 20. The holder 66 is positionably mounted on the frame 20 so as to permit more or less clockwise movement of the handle 24 to its extreme position, thereby refining a series of positions of the motor carriage 23. This in turn determines the extent of penetration of the router bits 25 so as to develop a perfect fit, since the router carriage 21 is directly coupled to the motor through a power train which will now be described.

Router carriage power trai/1 The power train for moving the router Carriage 21 can be most readily appreciated from a consideration of FIG. 6 on the fourth drawing sheet. There, the motor 53 is seen to be equipped with a sprocket 67. The sprocket 67 is coupled by means of a chain 68 to a second sprocket 69 which is mounted on a shaft 70. The shaft 70 is journaled in a bearing 70a secured to the underside of the motor carriage 23. The sprocket 69 is equipped with an eccentrically located pin 71 to which is connected a long link 72. The other end of the long link 72 is rotatably connected to the underside of the router carriage 21 as at 73 (see FIG. 3 on the third drawing sheet). Thus, as the motor 23 rotates, the rotational motion is transmitted through the sprocket and chain drive (elements 67-69) to reciprocate the linkage 72 and thus the router carriage 21.

The motor 53 also provides power for interruptedly moving the board carriage 22 by means of a cam-type connection which will now be described.

Board carriage cam drive Reference is now made to FIG. 4, where again the motor is designated 53 and, in a cut-away portion, the cam sprocket is designated again by the numeral 69. Oppostte the pin 71 providing a journal for the long link 72, the cam sprocket 69 is equipped with a pin 74. The pin 74 is adapted to engage a ratchet-type rack generally designated 75 and which is provided on a block 76 secured to the underneath portion of the board carriage 22. This can be appreciated from the showing in FIG. 8, wherein the rack 75 is encircled and seen with its associated mounting block 76 as at B-this portion being seen in larger scale in FIG. ll.

Referring now to FIG. l1, the rack 75 is seen to be equipped with slots 77 through which bolts 78 project from the block 76. Urging the rack rearwardly, i.e., toward the router bits 25, are springs 79 suitably mounted on guide rods 80 carried by the block 76. The springs 79 project into slots 81 provided as part of the rack 75, and the springs 79 insure that the rack 75 is urged against the motor table 23 as at 82 in FIG. 3 (on the third drawing sheet). This insures that the cam post 74 necessarily engages the ratchet rack 75.

The block 76 (see FIG. l) may also be equipped with a depending switch actuator 83 which is adapted to engage a switch (not shown) on the right-hand inside of the frame 20 (as seen in FIG. 1) to shut oit the motor 23 at the end of a given traverse of the board carriage 22.

Although the board carriage 22 and the router carriage 21 have predetermined movements developed from the cani sprocket 69 and through the long link 72 relative to the router carriage 21, and the ratchet racket 75 relative to the board carriage 22, I iind it advantageous to provide a means for correlating these two movements at the dovetailing site, and for this purpose make use of a guide rack generally designated 84.

Guide rack The guide rack 84, as seen in the encircled portion A of FIG. 8, is secured to the board carriage 22 as seen in FIGS. 13 and 14. The rack itself is seen in enlarged scale in FIGS. 9 and 10 and is characterized by a series of entrance grooves 85 spaced by projecting, curved-ended iingers 86. Cooperating with the rack 84 is a pilot pin 87 (see FIG. 4) carried by the router carriage 21. Thus, as the router carriage 21 is reciprocated, the pilot pin 87 enters successive grooves 85 to properly position the router bits 25 for the next cutting operation.

Additionally, the rack 84 is provided with integral upstanding portions as at 88 (compare FIGS. 9 and 10), which serve to space the end board 27 relative to the side board 32 as seen in FIG. 14 when a flush or non-lip joint is required. On the other hand, the spacers 88 serve to support the lip 34 in the fashion seen in FIG. 13 when a lip drawer is being developed.

Example As a specific example of the inventive machine, the illustrated embodiment has a board carriage measuring about 18 x 18, with the frame measuring about 28" from front to rear. This sized machine is adapted to simultaneously dovetail four boards, thereby providing the sides and ends of a complete drawer. The guide rack 84 is 12% long by 2% wide, having slots 13/3" on 7/s centers. Thus, the stroke of the router bits is 1%". The machine thus described is equipped with high speed router motors capable of developing 21,000 r.p.m. so as to develop dovetail joints even in plywood. The operation is speedy, with the motor 53 developing 12 r.p.m. on the cam sprocket 69. The total weight of the machine is about 150 pounds, making the same readily portable and, as pointed out before, is c-apable of dovetailing boards of varying thicknesses, over the conventional range of 3/s1/2". The operation of the inventive machine will now be described.

Operation The rst step is, of course, to clamp the side boards 32 and end boards 27 in the orthogonaliy-related positions seen in FIGS. 13 and 14. This is done through operation of the clamps 43 and 44, respectively. Thereafter the handle 24 is moved clockwise as seen in FIG. 7 to engage a recess or detent 66a in the positionable holder 66. The setting of the holder 66 is dependent upon the thickness of the boards employed, the position of the holder 66 determining the extent to which the router bits 25 move toward the operating end facing the viewer in FIG. 1. Here, it will be appreciated that not only must there be a setting for diiierent thickness boards, but even in a given thickness-say, 1/zthere will be a variation from batch to batch.

In the operation, it is preferred to have the handle 24 actuate both the main motor 53 and the router motors 49, this assuming the main switch 59a is suitably positioned. This actuation of the motors 53 and 49 is sequential, with the router motors 49 iirst being started so as to insure bringing the router bits 25 up to speed before any engagement is made with the side boards 32.

Thereafter, the rotation of the sprocket 67 coupled to the motor 53 turns the cam sprocket 69 to reciprocate the router carriage 21 and also to step the board carriage to the right in FIG. 1 by virtue of the camming pin 74 entering the various openings 75a in the ratchet rack 75. In the operation of the machine, I prefer to have the pilot pin 87 control the operation, as compared to the cam pin 74. Thus, there is a discrete time during each step when the cam pin 74 becomes disengaged from the ratchet rack 75 and wherein the engagement of the pilot pin 87 with the guide rack 84 governs the relative movement of the router bits 25 and the board carriage 22.

The spring-loading of the ratchet rack 75 urges the Same toward the motor carriage 23, the edge of which as at 32 may provide a rail to insure proper setting of the block 76 thereagainst. The board carriage 22 is seen to be equipped with a slot 22a permitting the block 76 to depend into abutting relation with the motor carriage 23.

The length of travel of the bits is indicated in FIG. 14 where the numeral 25a designates the maximum left position of the bits 25 during dovetaiiing. This results in a rounded tenon portion 33 for perfect mating with the rounded mortise portion 31. As mentioned previously, the depth of the mortise portion 31 is xed by the adjusting screw 63.

While in the foregoing specification a detailed description of an embodiment of the invention has been set down for the purpose of explanation thereof, many variations in the details herein given may be made without departing from the spirit and scope of the invention.

I claim:

In a dovetailing machine for drawers, a frame equipped with first and second carriages arranged for orthogonal movement relative to each other in vertically-spaced horizontal planes, the first of said carriages being equipped with a pair of cutting bits mounted for rotation about vertical axes and positioned adjacent one edge of said second carriage, said second carriage being equipped with clamp means for supporting a first board in vertical condition and a second board in horizontal condition, with said iirst board being located closer to said one edge than said second board, a motor on said frame for moving both of said carriages, linkage means coupling said motor to said iirst carriage for reciprocating the same, cam and ratchet rack means coupling said motor to said second carriage for interruptedly stepping said second carriage in one horizontal direction, and a guide rack providing spaced entrance grooves and elongated ngers secured to said second carriage along said one edge, a pilot pin upstanding on said first carriage between said cutting bits cooperating with the grooves of said guide rack for controlling the relative movement of said carriages between steps of said second carriage said guide rack being equipped with upstanding integral projections on said fingers intermediate the length thereof adapted to support the orthogonally-related boards in spaced-apart relation so as to permit development of both iiush and lip-type drawers on said machine without special adjustment.

References Cited by the Examiner UNITED STATES PATENTS 125,282 4/1872 Gear et al 144-87 478,544 7/1892 Cordesman et al 14487 724,850 4/1903 Grim 144-87 1,085,390 1/1914 Strozier 144--87 2,893,449 7/1959 Hadnagy 144-87 WILLIAM W. DYER, IR., Primary Examiner.

DONALD R. SCHRAN, ANDREW R. JUHASZ,

Examiners. 

